title: Organic acids associated with saccharification of cellulosic wastes during solid-state fermentation.
abstract: Saccharification of five cellulosic wastes, i.e. rice husks, wheat bran, corn cobs, wheat straw and rice straw by three cellulytic fungi, i.e. Aspergillus glaums MN1, Aspergillus oryzae MN2 and Penicillium purpurogenum MN3, during solid-state fermentation (SSF) was laboratory studied. Rice husks, wheat bran, and corn cobs were selected as inducers of glucose production in the tested fungi. An incubation interval of 10 days was optimal for glucose production. Maximal activities of the cellulases FP-ase, CMC-ase, and p-glucosidase were detected during SSF of rice husks by P. purpurogenum; however, a-amylase activity (7.2 U/g) was comparatively reduced. Meanwhile, the productivities of FP-ase, CMC-ase, and β-glucosidase were high during SSF of rice husks by A glaucus; however, they decreased during SSF of corn cobs by P. purpurogenum. Addition of rock phosphate (RP) (75 mg P(2)O(5)) decreased the pH of SSF media. (NH(4))(2)SO(4) was found to be less inducer of cellulytic enzymes, during SSF of rice husks by A. glaucus or A. oryzae; it also induced phytase production and solubilization of RP. The organic acids associated with saccharification of the wastes studied have also been investigated. The highest concentration of levulinic acid was detected (46.15 mg/g) during SSF of corn cobs by P. purpurogenum. Likewise, oxalic acid concentration was 43.20 mg/g during SSF of rice husks by P. purpurogenum.
authors.affiliation: Department of Bioprocess Development, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934, Egypt. nouraelahmady@yahoo.com
authors.forename: Noura El-Ahmady
authors.initials: Nel-A
authors.lastname: El-Naggar
authors.forename: Mohammed Saad
authors.initials: MS
authors.lastname: El-Hersh
mesh_terms: D001230:Aspergillus / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D002264:Carboxylic Acids / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D019649:Food Industry; D005656:Fungal Proteins / Q000378:metabolism; D020869:Gene Expression Profiling; D006026:Glycoside Hydrolases / Q000378:metabolism; D007220:Industrial Waste; D012275:Oryza / Q000378:metabolism; D010407:Penicillium / Q000378:metabolism*; D014908:Triticum / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism
chemical_list: D002264:Carboxylic Acids; D003470:Culture Media; D005656:Fungal Proteins; D007220:Industrial Waste; D002482:Cellulose; D006026:Glycoside Hydrolases